A study of bacterial deoxysugars is carried out using two complementary approaches: 1. Detailed examination of individual enzymes involved in the biosynthesis of 6-deoxyhexoses. a. Thymidine diphosphoglucose-4,6-hydrolase, the enzymes initiating 6-deoxyhexose biosynthesis will be studied to increase our understanding of structure and function for "half-site" enzymes. The problem will be explored by: (1) specific chemical modifications of the enzyme protein; (2) studies concerning the process of enzyme-subunit association and dissociation; and (3) kinetic analysis with synthetic substrate and coenzyme analogues and studies on specific enzyme inhibitors. b. Comparative studies will be performed on UDP-galactose-4-epimerase, another "half-site" enzyme with analogous properties to TDPG-4,6-hydrolase. c. TDP-L-rhamnose dehydrogenase and TDP-6-deoxy-L-talose-dehydrogenase will be purified and characterized. Studies using synthetic substrate and coenzyme analogues will be performed. 2. In a synchronized bacterial culture, the levels of enzymes involved in deoxyhexosebiosynthesis will be correlated to 6-deoxyhexose incorporation into cell wall lipopolysaccharide, as well as to cell surface related phenomena such as immuno response or agglutination.